What action was successfully performed using the fertile F1 hybrids and one of the parental species?
Answer
Backcrossing
The research extended to backcrosses, where the F1 hybrids were mated back to one of the parent species, specifically the Red deer, and also successfully mated back to the Père David's deer.

Related Questions
Which species was most notably crossed with the Père David's deer in documented hybridization studies?What characteristic was specifically noted about the first-generation (F1) hybrids resulting from the Père David's deer imes Red deer cross?Why is the Père David's deer largely extant today?The successful hybridization between Père David's deer and Red deer is noteworthy because they belong to which different taxonomic ranks?What action was successfully performed using the fertile F1 hybrids and one of the parental species?What is the current status of natural hybridization involving Père David's deer?What management consequence arises from the high genetic compatibility observed between Père David's deer and Red deer?What was the result of mating F1 hybrids back to the Red deer parent species?What is the primary conservation objective for managing Père David's deer populations?What specific aspect of reproductive biology is investigated by comparing the viability rates between reciprocal crosses involving Père David's deer and Red deer?